NCBC-643: TimeSpan expiration under 1 sec results in an infinite timeout

Change-Id: Ie59854217cdb5e1f9a71c19a77528f50b3f486bb
Reviewed-on: http://review.couchbase.org/42680
Reviewed-by: Jeffry Morris <jeffrymorris@gmail.com>
Tested-by: Jeffry Morris <jeffrymorris@gmail.com>